//
// Created by 吴锐 on 2022/2/23.
//

#include<iostream>

using namespace std;

int main(){

    int a = 10;
    int &b = a;

    int c = 20;

    b = c;

    cout << a << endl;
    cout << b << endl;
    cout << c << endl;

    return 0;
}